Ask Sail: Staysail Loads - Sail Magazine

Ask Sail: Staysail Loads

I would like to add an inner forestay to my Hughes Columbia 40. The sail for this is 350 square feet. What safe working load would I need for an exit block for the mast as well as jib tracks and leads?
Author:
Updated:
Original:

Larry Schnell, Cooperstown, NY
Q: I would like to add an inner forestay to my Hughes Columbia 40. The sail for this is 350 square feet. What safe working load would I need for an exit block for the mast as well as jib tracks and leads?

Win Fowler Replies
A: The load on a sail is proportional to the sail area times windspeed squared. The formula is: (sail area [in ft2] x windspeed2 [in knots]) coefficient = load. In our shop we use a coefficient of 0.00431. For a 350ft2 sail in 30 knots this yields a load of 1,358lb. In 40 knots of wind, the load climbs to 2,414lb. We assume that this is the load on both the sheet and the halyard. I would think a safe working load of 2,500lb would be pretty good.

Got a question for our experts? Send it to sailmail@sailmagazine.com 

Related

Photo-by-Adobe-Stockpics721-2048x

Webinar: Navigating Post-Dorian Abaco

On Thursday, October 22 at 6 pm ET, Navigare Yachting presents a webinar on what to expect from Abaco post-Dorian. The event will feature the authors of The Cruising Guide to Abaco, Steve Dodge and his sons Jon and Jeff.Hurricane Dorian hit Abaco in early September of 2019 and ...read more

LunaRossaBoat2

Luna Rossa Prada Pirelli Christens “Boat 2”

Hot on the heels of the UK’s Britannia and the United States’ Patriot, Italy’s new AC75 Luna Rossa, formerly known as Boat 2, was christened in Auckland, New Zealand, this morning. As the moniker suggests, it was Team Luna Rossa Prada Pirelli’s second design. In his christening ...read more

m7803_DSCF6698-1

Challengers Christen Britannia and Patriot

October 16 proved an exciting day for America’s Cup fans with the christening of both the UK’s Britannia and America’s Patriot. Britannia will be helmed by four-time Olympic gold medalist and America’s Cup winner Sir Ben Ainslie. Olympic Gold medalist Giles Scott will serve as ...read more

HookPromo

Defender Product Spotlight: Lowrance Hook Reveal

Defender product expert Alex Lyons explains the benefits of HOOK Reveal’s new FishReveal technology: “DownScan sonar uses high frequencies to provide a picture-like image of the sea floor. The traditional sonar’s lower frequencies are best suited for locating fish in the water ...read more

701820_promo

Defender Product Spotlight: Lumitec Poco Lighting Control

Several key features of the Lumitec Poco Lighting Control system stand out right away. First, it is a 2-wire system, so the average wiring-savvy boater can install or retrofit the controls without an engineering degree. Second, it works with any Power Line Instruction (PLI) ...read more

Isotherm

Defender Product Spotlight: Isotherm Refrigeration Component System

Retrofitting a refrigeration cooling system has never been easier thanks to Isotherm’s quick mount bracket. And installation is more than half the fun of boat projects, right? These refrigeration component systems also have one of the smallest footprints on the market, and the ...read more

WaveBreaker

Defender Product Spotlight: Superior Wave Breaker Life Raft

Designed for a hardcore offshore application, Superior Life-Saving’s Wave Breaker life rafts are heavy duty, easy to board, insulated and feature many benefits, including an industry-leading 4-square-feet of space per person aboard. The Wave Breaker line of life rafts is ...read more

003536D2

Defender Product Spotlight: Lewmar Heavy Duty Inflatable Yacht Fenders

After using the Lewmar Heavy Duty Inflatable Yacht Fender, you’ll never want to hoist another fender aboard your cruiser or sportfish. Made from 30% heavier material than the next best brand, it features 15% more tensile strength to provide protection for your hull when docking ...read more